def login(username, password):
    if username == 'admin' and password == '123456':
        return '登录成功'
    else:
        return '登录失败'

def add(a, b):
    """两位数加法计算器"""
    if not (isinstance(a, (int,float)) and isinstance(b,(int,float))):
        return 'error,非数字'
    if -99 < a < 99 and -99 < b < 99:
        return a+b
    else:
        return 'error,数据的范围必须大于等于 -99 并且小于等于99'


